This action switches to, and launches if necessary, the specified application. It is the equivalent of using the macOS App Switcher, or launching the application by any means.

• Select the App from the “Activate:” Popup
• In the same Popup, choose how to identify the app: (v9.0+)
  • Match Using Default (first by path, then by Bundle ID if needed)
  • Match Only by Path
  • Match Only by Bundle ID
• Check the Options To Use
  • Check to Show all windows or Unchecked to show only the FrontMost Window
  • Reopen the app's initial window(s)
  • If the application is already at the front, you can choose to
    • leave it there.
    • or switch to the previous application.
    • or bring its windows to the front.
    • or reopen its initial windows.
    • or hide it.
    • or hide other applications.
    • or quit it.

This Action requires that you select the App during Macro design, and you cannot use a Variable for the name.

However, there are several alternatives that will allow you to use a Variable for the App Name:

1. Use Variable to set the Frontmost App. This will have the same effect as Activating the app.
2. Activate Application by Name String -- Custom PlugIn – A third-party custom PlugIn that will allow you to set the application by its name in a Variable.
3. Use the open shell command with the Execute a Shell Script action.
4. Use the Open an Application action with a variable path.

• Open a File Folder or Application
• See all Actions

• %Application%n%
• %CurrentApplication%
• %LastApplication%
• See all Tokens

• Keyboard Maestro Forum topics about Activate a Specific Application